1. Field of the Invention
The present invention relates to an earthing structure of an earthing truck, and more particularly, to an earthing structure of an earthing truck, which simplifies the earthing structure for discharging a residual current in a bus chamber and a cable chamber of a distribution panel to the outside through the earthing truck, prevents the breakaway of the earthing truck, and also improves the earthing short-time capability.
2. Background of the Invention
In general, an earthing truck is a kind of earthing device that grounds the residual current on the load side or the bus side of a distribution panel to the earth to prevent safety accidents due to the residual current that can occur to an operator during repair or inspection of the load side equipment.
Moreover, FIG. 1 is a perspective view showing a distribution panel including a conventional earthing truck, and FIG. 2 is a perspective view showing a conventional earthing truck.
As shown in FIGS. 1 and 2, a distribution panel 1 with a conventional earthing truck includes a bus chamber 10, a cable chamber 20, a cutoff chamber 30, a Low Voltage (LV) chamber 40, and a Power Transfer (PT) chamber 50.
The cutoff chamber 30 is provided covering the bus chamber 10 and the cable chamber 20 and includes a breaker (not shown) that can electrically disconnect or connect the bus chamber 10 and the cable chamber 20, and the breaker provided in the cutoff chamber 30 may be drawn in and out.
The connection between the bus chamber 10 and the cable chamber 20 is cut off by the breaker's cutoff function so that power transmission from the bus chamber 10 to the cable chamber 20 or power transmission from the cable chamber 20 to the bus chamber 10 is blocked.
The bus chamber 10 receives high voltage power from a transmission line, and the cable chamber 20 receives high voltage power from the bus chamber 10 or low voltage power converted from high voltage power and supplies it to the load side through various paths.
The LV chamber 40 is a space in which a distribution panel control unit is mounted, and the PT chamber 50 is a space in which a PT for sensing a voltage is mounted.
In the conventional distribution panel 1 configured as described above, the earthing truck 60 grounds the residual current of the bus chamber 10 and the cable chamber 20 and discharges it to the outside while moving in the cutoff chamber 30. Such a conventional earthing truck 60 includes a frame 61, a moving part 62, a terminal connection part 63, a terminal connection bar 64, and a finger structure 65.
Therefore, as the earthing truck 60 moves, when the terminal connection part 63 is connected to a terminal connection part (not shown) provided in the bus chamber 10 or a terminal connection part (not shown) provided in the cable chamber 20, the residual current remaining in the bus chamber 10 or the cable chamber 20 is discharged to the outside through the terminal connection part 63, the terminal connection bar 64, the finger structure 65, and the guide member 66, so that the operator may work safely in the bus chamber 10 or cable chamber 20.
However, in relation to the above conventional earthing truck 60, since the finger structure 65 provided in the earthing truck 60 moves inside the cutoff chamber 30 while being inserted into the guide member 66, there is no additional force applied to fixedly support the earthing truck 60, so that there is a problem that the earthing truck 60 easily shakes or is easily detached from the moving path during the movement due to an external impact.
Furthermore, since the finger structures 65 and the like are provided in the earthing truck 60 rather than in the cutoff chamber 30 of the distribution panel 1, the structure of the earthing truck 60 is complicated, so that each component of the earthing truck 60 is easily damaged when moved.